The Italy-U.S. Cooperative Science Project with the University of Milan will concentrate on the development and testing of two new instruments for the study of the reactions of oxygen with hemoglobin inside the red cell in fresh whole blood. The first of these is the measurement of the amount of each hemoglobin species which exists in the sample drawn (10 microns 1), ie. reduced oxy, met and carboxy hemoglobin. The second instrument, using lasers, will permit the measurement of both the kinetic parameters; i.e., Ron, Ton, Toff, and Roff, and the dissociation curve (ODC) inside the cell using only 1/2 ml of whole blood or less.